As examples of image display systems, billboard and other sign-based advertising techniques have existed for many years. Typically a billboard or sign-based advertisement is a general advertising message intended to pertain to a large number of people viewing the advertisement. Billboards and other large signs (such as bus-stop signs) typically display the same ad for an extended period of time (e.g., a few months), due to the cost of removing an old ad and putting up a new ad. More casually, corkboards are often placed in public places (e.g., coffee shops, universities, parks) where people can post their own ads (e.g., “roommate needed” or “bicycle for sale”), but there is a lack of ability to monetize these ads.